Rabbi Elazar explains that when God has mercy on Yisrael, He suppresses the attribute of Judgment by dropping two tears (signifying two attributes of Judgment) into the Great Sea (signifying the Sea of Wisdom) in order to sweeten them. In this way, He turns the attribute of Justice into the attribute of Compassion.
Rabbi Yitzchak then clarifies the apparent contradiction in the verse, "Behold, Egypt marched after them," explaining that it refers to the deposed and powerless supernal minister of Egypt.
Finally, Rabbi Aba answers Rabbi Yosi's question regarding the verse, "Behold, the day of Hashem comes..." This, we are told, refers to the day on which God will Judge the heathen nations and their ministers will fall from power.
All our negative impulses originate in a supernal negative force or evil angel that attempts to influence and manipulate us throughout our day. Each time we yield to an evil urge, we strengthen that supernal angel. His influence grows stronger in the world he is free to inflict judgment upon us.
Every time we resist a wicked impulse, we diminish the negative angel's power. In addition, each time we shed tears of repentance for our misdeeds and make the effort to abolish the traits that originally caused them, we awaken the compassionate force of mercy, which tempers and sweetens judgments decreed against us. Thus, we learn that our every deed is vital to the world and stands like a lock-keeper with his hands upon the wheel: a turn to the left, and the river of Light is shut out; a turn to the right, and it pours through again in a torrent of blinding Glory that overflows its banks, washing away darkness and judgment.
Our own tearful meditation upon these holy verses turns the wheel to the right, unleashing mercy, compassion, and clemency into our world. These awesome forces of kindness ensure that our Redemption unfolds in a gentle and pleasant manner, as opposed to one filled with pain and suffering.